Precious-metal plate



80 Drawing.

Patented Aug. 20, 1929.

UNITED STATES PATENT, OFFICE.

VICTOR D. DAVIGNON, OF ATTLEBOBO, MASSACHUSETTS; ASSIGNOB TO GENERAL PLATE COMPANY, OF ATTLEBORO, MASSACHUSETTS, A CORPORATION OF RHODE ISLAND.

PRECIOUS-METAL PLATE.

Application filed May 8,

This invention relatesto plated metal and methods of producing the same, and particularly concerns an improvement in plated products which comprises a backing of relatively cheap low specific gravity metal surfaced with a comparatively thin layer of precious metal.

Heretofore in producing precious metal plate such as gold or silver plate it-ha's been "use an alloy containing aluminum for securing a low specific gravity. So that this alloy may be worked by mill processes of alternate mechanical attenuation and annealing the constituents of this alloy and their relative proportions preferably are such that the alloy is sufliciently malleable or ductile when cold to permit attenuation by the usual mill operation of rolling or drawing and to permit annealing after the alloy has been hardened as a result of the attenuating operation. 7

- As satisfactory for aluminum alloy for economic use in producing gold late by alternate rolling and. annealing I ave found that the alloy may be compounded so as to contain from about 2 to 10 percent by weight of aluminum and a material proportion of copper. Preferably copper is the only metal other than aluminum present in substantial amount, but if desired small amounts of other metals such asrzinc, tin, nickel, etc.-

commonly employed for imparting special properties may be incorporated. This alloy is of materially lower specific gravit' than that heretofore used in connection wit the production of precious metal plate and is malleable when cold, while by a process hereinafter described it may be annealed to permit production of plate by machinery commonly employed in t e art'for this purpose. If the aluminum content exceeds 10 percent by weight of the alloy the latter may be ecomonically rolled only when hot, which, if the precious metal used is a gold 1926. Serial No. 106,556.

allo containin gol renders t e alloy impractical for use in production of gold plate because the gold alloy can satisfactorily be rolled by usual millmachinery only when cold.

' As an exampe of the improved process of producin plate, but without limitation thereto, I plate of alloy containing by weight 92 percent copper and 8 percent aluminum, said plate being about three-quarters of an inch thick, 3 inches wide, and 14 inches long. On one or both sides of the plate I now place a sheet of solder, as for example silver solder about .003 of an inch thick, and on this sheet place a sheet of gold alloy, as for exmay form the backing from a a substantial proportion of i ample 14 carat copper-gold alloy, the thickness of e gold alloy sheet being such that its weig t is from one-half to one-four hundredth of the weight of the backing. The built up plate of base metal, gold alloy, and solder I place in a soldering furnace and after heating to the soldering temperature subject it to a pressure of about 5 tons, which with use of suitable flux as hereinafter described effects soldering of the gold alloy to the backing. 'After the solderin operation the billet is allowed to cool an then is passed between the rolls of a mill to reduce its thickness, the rolling operation being repeated with successive reduction in thickness of the material until the material reaches a degree of hardness necessitati annealing be ore it may be further reduce The material is thenannealed by a process tion, and for this purpose I place on the sheet of silver solder or on the faces of the backin and gold alloy in contact with the silver sofler suitable flux, having found satisfactory for this urpose potassium bifluoride, calcium chlori e, a; mixture of one part calcium chloride and two parts otassium bifluoride, cryolite, and sodium uoride, these substances preferably being mixed with borax. -As examples of fluxes, but without l mitation thereto, I may use a mixture consisting of one-half borax and one-half cryolite, or two-thirds borax and one-third sodium fluoride. Conveniently the flux may be applied in the form of an aqueous solution in which the parts may be dipped, or the parts may be sprayed with the solution, or I may apply the flux in the form of a powder,

I As an example of a satisfactory annealing operation, but without limitation thereto, I may heat-treat the material by raising it to a temperature of from about 900 to 1300 degrees Fahrenheit in an annealing furnace and suddenly plun e it while at that temperature into a quenc ing liquid, as for example water at room temperature, which will render both the gold alloy and aluminum alloy backing suflicientl malleable or ductile for continuation of t e attenuating operation.

I have also found as suitable for alloy, es-

pecially where wear resisting qualities are desire that some of the aluminum in the above example may be substituted by iron or .manganese. As an example of such alloy, but without limitation thereto, it may consist of'about 6.5 percent by weight of aluminum, about 1 percent by weight of-either iron or manganese, with the remainder. cop

, a substitute for aluminum I have found suitable a mixture-of silicon and manmalleable.

backing contains from about 2 to 10 percent ganese, the latter being sufiicient in amount to counteract the hardeningefiect of the silicon. As an example ofsuch alloy, but without limitation thereto, it may consist of about 4 to 4.5 percent silicon and about 1 percent manganese with the remainder cop- My improvement is distin ished from prior processes and products m that I employ as a backing a cold-malleable, copper aloy containingsuflicient aluminum or like low s ecific gravity metal, such as silicon, materially. to. reduce its specific gravity, a homogeneous union bein effected between the backing and the preclous metal, and the product'bemg heat treated between the attenuating operations to render it ductile or In the preferred example the of aluminum, 8 percent being satisfactory,

- and the union between the backing and precious metal is effected y solderin in the presence of a flux eliminating the de eterious effect of aluminum oxide on the soldering, while annealing is effected by heat treatment comprising heating the billet and plunging it into cold quenching liquid while at a temperature of about 1000 degrees Fahrenheit.

It will be understood that wide deviations may be made from the examples of the invention herein described without departing from the spirit of the invention.

Claims 1. That. method of producing a plated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the lattercontaining sufiicient aluminum materially to reduce its specific gravity but not more than about 10 percent by weight, and being sufliciently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises effecting a homogeneous union of relatively thick pieces of said gold alloy and backing, and attenuating the united materials by repeated rolling or drawing thereof while cold.

2. That method of producing a plated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the latter containing sufiicient aluminum materially to reduce its specific'gravity but not more than'about 10 percent by weight, and being sufficiently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises effecting a homogeneous union of relatively thick pieces of said gold alloy and backing; attenuating the united materials by repeated rolling or drawing thereof while cold, with heat treatment thereof between rolling or drawing operations for annealing the backing after the same has been hardened by said operations.

3. That method of producing a plated product consisting of a layer of gold alloy ona backing of copper-aluminum alloy, the latter containing sufiicient aluminum mate- -rially to reduce its specific gravity but not more than about. 10 percent by weight, and being sufliciently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises effecting a homogeneous union of relatively thick pieces of said gold alloy and backing by soldering one to the other in the presence of a flux capable of effecting soldering and eliminating the deleterious eifects of aluminum oxide,,and attenuating the united materials by repeated rolling or drawing thereof while cold.

4. That method of producing a plated product consisting of a layer of gold alloy on a backing of cop r-aluminum alloy, the latter containing 'su cient aluminum materially to reduce its specific gravity but not more than about 10 ercentby weight, and being sufliciently ma cable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises eflecting a homogeneous union of relatively thick pieces of said gold alloy and backing by soldering one to the other in the presence of a flux capable of effecting soldering and conthe backing has been 7 tween rolling taining a halogen salt of an alkaline earth, and attenuating the united materials by repeladted rolling or drawing thereof while co 5. That method of producing aplated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the latter containing sufficient aluminum materially to reduce its specific gravity but not more than about 10 percent by weight, and being sufficiently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises effecting a homogeneous union of relatively thick pieces of said gold alloy and backing by soldering one to the other in the presence of a flux capable of effecting soldering and containing borax mixed with a halogen salt of an alkaline earth, and attenuating the united materials by repeated rolling or drawing thereof while cold.

6. That method of producing a plated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the latter containing suflicient aluminum materially to reduce its specific gravity but not more than'about 10 percent by weight, and being sufiiciently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises efl'ecting a homogeneous union of relatively thick pieces of said gold alloy and backing; attenuating the united materials by repeatedly rolling or drawing them while cold, andbe- I tween rolling or drawing operations, after hardened thereby, heating said materials and quenching them at such temperatures as will render the backing sufficiently malleable for said operations to be continued.

7. That method of producing a plated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the

latter containing suflicient aluminum materially to reduce its specific gravity but not more than about 10 percent by weight, and being sufliciently malleable to permit substantial attenuation thereof by rolhng or' drawing while cold, which comprises etfecting a homogeneous union of relatively thick pieces of said gold alloy and backing; attenuating the united materials by repeatedly rolling or drawing them while cold; and beor drawing operations, after the backing as been hardened thereby, annealing said backin by heating said mate-v rials and plunging t em, while at a tem erature of about 1000 degrees Fahrenheit, into cold quenching liquid, to permit said operations to be continued. g

8. That method of producing a plated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the latter containing by weight not more than about 10% of aluminum but enough materially to reduce its specific gravity and being sufliciently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises effecting by soldering a substantiall homogeneousuinion between relatively thic pieces of said gold alloy and backing; and attenuating the united materials by rolling or drawing thereof while cold, with heat treatment thereof between the rolling or drawing operations for annealing the backing after the same has been hardened by said operations.

9. That method of producing a plated product consisting of a layer of gold alloy on a backing of copper-aluminum alloy, the latter containing by weight not more than about 10% of aluminum but enough materially to reduce its specific gravity and being sufliciently malleable to permit substantial attenuation thereof by rolling or drawing while cold, which comprises placing between relatively thick pieces of said gold alloy and backing a thin sheet of silver solder and a soldering flux, the latter containing borax and a halogen salt of an alkasaid rolling or drawing operations to be continued, said annealing comprising heating said materials and while at about 1000 degrees Fahrenheit quickly quenching them with water at about room temperature.

10. Plated products comprising a layer of gold alloy containing a material amount of gold on a backing of copper-aluminum alloy, the latter capable of being attenuated by rolling or drawing while cold and contaming a material proportion of copper. and from about 2 to 10 percent by weight of aluminum. L

11. Plated products comprising a layer of gold alloy containing a material amount of gold on a backing of copper-aluminum alloy, the latter capable of being attenuated byrollingor .drawing while cold and containing a material proportion of copper and about 8' per cent by weight of aluminum.

12. Plated products comprising a layer of gold alloy containing a material amount of old on a backing which can be attenuated y rollin or drawing while cold and consisting 0 about 8 percent aluminum and about 92 of cop r.

13. plated product comprising a layer by weight of percent by weight of gold alloy on a backing of copper alloy,

the gold" alloy containing at least 25 percent,

by weight of gold, the base metal content of the copper alloy having sufiicient aluminum materially to reduce the specific gravity of said alloy, said copper alloy having suflicient copper relative to the base metal content to render the alloy capable of being attenuated by rolling or drawing while cold,

' the gold alloy containing at least 25 percent by weight or gold, the copper alloy being predominantly copper and containing sufiicient aluminum materially to reduce its specific gravity but not enough aluminum to prevent it from being attenuated by rolling or drawing while cold, the aluminum content of said copper alloy being in all cases atlleast 2-percent' by weight, and, when the I said copper alloyisexclusively copper and aluminum, the aluminum content not exceeding 10 percent by weight.

36 1.5. A plated product comprising a layer of gold alloy containing a material amount of gold on a backing which can be attenuated by rolling or drawing while cold and consisting of from about 2 to 10 percent by weight of aluminum with the remainder H copper.

16. A plated product comprising a layer of 14 carat gold on a backing of copper-'- aluminum alloy which can be attenuated by rolling or drawing while cold and containing about 92 percent of copper and ,about 8 percent of aluminum.

17. Plated products comprising a layer of gold alloy containing at least 25% by weight of gold on a backing of copper alloy, the latter capable of being attenuated by rolling or drawing while cold and containing a ma.-'

terial proportion of copper and from about 2 to 10% by weight of aluminum.

18. A plated product comprising a layer of 14 carat gold on a backing of copper al- 10y, the latter capable of being attenuated by rolling or drawing while cold and com taining. a material proportion of copper and suflicient aluminum materially toreduce its u specific gravity but not more than about 10 percent by'weight of aluminum.

In testimony whereof, I have signed iny name to this specification.

V. D. DAVIGNON. 

